Malthus' population theory is still wrong

In this article, I try to answer the question-"Will Malthus continue to be wrong?", one of the 125 most challenging scientific questions raised by Science at its 125th anniversary ceremony, through a comprehensive review and analysis of historical backgrounds, population growth vs. economic development trajectories in recent decades, current new challenges, and future perspectives. Based on evidence from various theoretical and empirical studies in multiple fields, I conclude that Malthus' initial population theory is wrong in the past, present, and future. It has also been recognized that the new Malthusianism, which warned societies that quick population growth due to high fertility would put pressure on natural resources and the environment, and proposed birth control programs with voluntary contraception use, has made useful contributions to human development in the past decades. Given the fact that China's population has already entered the era of very slow growth and will decline in a dozen years, could we (as scientists) rest without worries about natural resources and environmental protections? Our answer is "No", because scientific research and policy analysis need to be strengthened to better understand the impacts of changes in the number and structure of family households on energy consumption, population aging, and sustainable development. Various studies have shown that household size has been shrinking in recent years, causing a quick increase in the number of households (including many living alone or empty-nest elders). Consequently, while the population growth rate is largely reduced and will become negative in a dozen years, energy consumption will substantially increase because households (rather than individuals) are the primary units of energy usage. Aside from energy use, plenty of research evidence suggests that older adults who live in small "empty-nest" households have significantly worse cognitive function, self-rated health, and life satisfaction compared to those elderly who live with or nearby their children and grandchildren. Empirical data analyses also show that three-generation co-residence or nearby living arrangements increase the workforce participation of female adult children and associated financial and health benefits, since grandparents traditionally take on care responsibilities for grandchildren. The analysis indicated that the old parents benefit more from emotional care provided by their adult daughters and sons-in-law compared to sons and daughters-in-law. To strengthen natural resource and environmental protections as well as to face the serious challenges of population aging, we propose that China needs to take two major policy actions. First, strongly enhance scientific and technical innovations in the fields of clean and efficient energy, emission reduction, protection of soil and water resources from pollution, and preservation of biodiversity. Second, implement a policy to promote three-generation co-residence or nearby living arrangements to reduce the negative effects of shrinking households on energy consumption, population aging, and sustainable development, More specifically, referring to successful policy programs that promote three-generation families in Singapore, we suggest that: (1) implement nationwide economic incentive policies to encourage adult children to live with (or nearby) their old parents; (2) encourage and support young migrants from the poor northwestern regions to go back to their hometowns to develop business and to reunite with their old parents, or bring their left-behind old parents to live with them in the cities; (3) encourage older parents to live with (or nearby) an adult daughter and son-in-law, even if they have both a son and a daughter. This would not only be beneficial for taking better care of old parents, but would also gradually change the tradition of daughters marrying out of their own families, which would help to eliminate son preference and reduce the high sex ratios at birth in China. In sum, the policy to encourage three-generation co-residence or nearby living arrangements is a win-win program that benefits both the elderly and their children, which is useful to address the serious challenges of population aging. It is also an effective way to slow down the quickly growing number of households and thus significantly reduce energy consumption and enhance environmental protection and sustainable development.

Duke Scholars

Author Yi Zeng Medicine, Geriatrics